Hitherto, ignition control using a microcomputer (micom) in marine engines has been generally widely used. There is frequently used a method whereby, in a cold mode, the spark advance control is executed to improve the starting performance, while in a warm-up mode, spark delay control is executed to reduce the rotational speed for idling. The same applies to the case of the outboard motor.
On the other hand, in the outboard motor, the shifting operation for forward or reverse movement is executed through a jaw clutch. A structure which limits the engine start timing to the neutral mode is used from a viewpoint of safety.
The ignition timing at starting of the engine is set to a state in which spark advance is performed to a certain extent. In the spark advance state, there are advantages so that the starting performance is good and the rotational speed rises, so that the warm-up time can be reduced.
However, in the cold state, there is an inconvenience in that, even if it is intended to allow warm up during low speed operation of a ship, when the rotational speed is high the jaw clutch does not come into engagement, so that, for example, the shift cannot be set to forward.
It is an object of the invention to avoid the inconveniences of the above conventional example and, more particularly, to provide an ignition timing control apparatus for a marine engine in which the start warm-up mode of the engine is extremely easily set and, even before completion of the warm-up, the shifting operation can be executed, so that preparation of the engine for sailing can be carried out in an extremely short time.